1. Field of the Invention
The invention concerns a device for operating an articulated mast or boom connected to a boom base, and in particular a concrete placement boom carrying a placement hose on the end of the boom, which articulated boom includes at least three boom arms which may each respectively be limitedly pivoted relative to the boom base or relative to an adjacent boom arm about parallel horizontal articulation axes via respectively one drive unit, which boom base is mounted to a frame and is pivotable preferably 360° about a vertical axis. The operating device includes a control device for movement of the boom as well as a remote controller communicating with the control device via preferably a wireless data transmission pathway, which remote controller comprises a first and a second remote control device, each of which may be adjusted manually back and forth in at least one main control direction and thus providing an output signal. The control device comprises a computer supported co-ordinate transformer, responsive to the output signal from the first remote control device, via which the drive units for the redundant articulation axes may be operated in the one main control direction of the first remote control device in any rotation position of the boom base, and independent of the drive unit for the rotation of the boom base, for extending or retracting the articulated boom according to the pattern of a pre-determined path-slew relationship. The invention further concerns a large manipulator, particularly for concrete pumps, with an articulated boom connected to a boom base and a device for operation thereof as described above.
Mobile concrete pumps are conventionally controlled by an operator who is responsible for controlling, using a remote control device, the pumping as well as positioning the placement end of a hose provided at the tip of the articulated boom. The operator must control multiple rotational degrees of freedom of the articulated boom via the associated drive units with movement of the articulated boom in non-structured three-dimensional work space with due consideration of the construction site boundary conditions. The single axis operation has on the one hand the advantage that the individual boom arms can individually be brought into any desired position limited only by their pivot range. Each axis of the articulated boom and the boom base is therein associated with one main control direction of the remote control device, so that above all in the case the presence of more than three boom arms the operation is manageable. The operator must maintain control over not only the axes but also the hose end, in order to avoid the risk of uncontrolled movement of the hose end and therewith an endangerment of the construction site personnel.
2. Description of the Related Art
In order to simplify the manipulation in this respect, an actuation device has already been proposed (DE-A 43 06 127), in which the redundant articulated axes of the articulated boom are controllable collectively with one single control manipulation of the remote control device, in any rotational position of the boom base, independent of the rotation axes thereof. Therein the articulated boom carries out an extension and retraction movement which is easily overseen by the operator, wherein the elevation or height of the boom tip can in addition be maintained constant. In order to make this possible, the control device includes a remote control device controllable computer supported coordinate transmitter for the drive units, via which the drive units of the articulated boom are actuated in the one main adjustment direction of the remote control device independently of the drive unit of the rotation of the boom base with accomplishment of an extension or retraction movement of the articulated boom while maintaining a predetermined height of the boom tip. In a different main adjustment direction of the remote control device the drive unit or drive unit of the rotation axes of the boom base is operable independent of the drive units of the articulated axes with carrying out a rotation movement of the articulated boom, while in a third main adjustment direction the drive units of the articulated axes are operable independent of the drive units of the rotation axes with carrying out of a raising and lowering movement of the boom tip. For optimizing the movement sequence during the extension or retraction process, it is considered to be important therein that the drive units of the redundant articulated axes of the articulated boom are operable respectively depending upon the pattern of a path-slew characteristic. Further associated therewith is that the path-slew characteristic is modified in the coordinate transformer depending upon the value of bending and torsion moments related to load acting upon the individual boom arms. Further, there the path-slew characteristics are limited in the coordinate transformer depending upon the value of the boom arm movement spatial collision zones, in particular by predetermination or pre-programming of a highest and/or lowest articulation point.
The use of the computer supported coordinate transformer is limited when it is necessary to carry out movement sequences deviating from the predetermined path-slew characteristic of the articulated boom, for example in order to pass the boom through a narrow opening or when for a particular task a defined positioning or arrangement of the one or the other boom arms is necessary. In this case it has until now been necessary to switch from the computer supported boom control in cylindrical coordinates to an individual control of the individual articulated axes with an appropriate number of main adjustment directions in the remote control devices. Besides this, the risk associated with the individual operation of the axes must be accepted.